A consumer advocacy group is threatening to sue McDonald's for marketing unhealthy food to children.

The Center for Science in the Public Interest (CSPI) wrote a letter to McDonald's expressing their grievances. The group is giving McDonald's 30 days to remove toys from Happy Meals before formally filing the lawsuit.

Read more:

• Group says it will sue McDonald's over toys in Happy Meals to kids, calling them deceptive (L.A. Times)
• Letter from the Center for Science in the Public Interest to McDonald's (PDF)